A member of Waterloo Regional Police Service is under investigation by the province’s police oversight unit.

The Special Investigation Unit’s webpage says a sexual assault allegation was filed against a member of the service on Sunday March 10.

According to regional police, an officer was investigating a suspected impaired driver in the Township of Wellesley on Monday morning. An allegation of sexual assault was made during this time, police say.

The officer was not identified while the investigation is ongoing.

The SIU investigates incidents of serious injury, death or sexual assault allegations involving police.